export {}


let user= {name:'jshand',age:18}

// const name = user.name
// const {name} = user

//数组的结构
const users = ["张飞","刘备"]
const [zf,lb] = users


//基础类型
let name:string = "jshand";
// let username:string = "hello  "+name+" welcome "
//ES6   ES2015
let username:string = `hello  ${name} welcome `

let age:number = 18;
let success:boolean = true

//方法定义
function sum(numa:number,numb:number):void{
    console.log("两个数的加和 ： "+(numa + numb))
}


sum(10,20)



// // 这样不会报错
// let num: number = undefined;
// // 这样也不会报错
// let u: undefined;
// let num: number = u;



//ts ---- js
//String  JS
//Date  Float
//Number
//原生的 js 类型
let str1 = new String("123456")
let number = new Number(3.1415926535897)

console.log("number.toFixed(2) ",number.toFixed(2));

//js内置对象的函数
let tsStr:string = String("abc")


